Re: [PATCHv3 06/13] run-command: add an asynchronous parallel child processor

From: Stefan Beller <sbeller@google.com>
Date: Sep 22, 2015, 21:31 UTC
Message-ID: <CAGZ79kYwMrpU-gW6FsbH1W4TRPisZH9GJoyZ6hoimXdxz4HCYQ@mail.gmail.com>
In-Reply-To: <xmqqtwqm2puk.fsf@gitster.mtv.corp.google.com>

On Tue, Sep 22, 2015 at 12:53 PM, Junio C Hamano <gitster@pobox.com> wrote:

Show 14 quoted lines

> Stefan Beller <sbeller@google.com> writes:
>
>> So how would you find out when we are done?
>
>         while (1) {
>                 if (we have available slot)
>                         ask to start a new one;
>                 if (nobody is running anymore)
>                         break;
>                 collect the output from running ones;
>                 drain the output from the foreground one;
>                 cull the finished process;
>         }
>

Personally I do not like the break; in the middle of the loop, but that's personal preference, I'd guess. I'll also move the condition for (we have available slot) back inside the called function.

So I am thinking about using this in the reroll instead:

    run_processes_parallel_start_as_needed(&pp);
    while (pp.nr_processes > 0) {
        run_processes_parallel_buffer_stderr(&pp);
        run_processes_parallel_output(&pp);
        run_processes_parallel_collect_finished(&pp);
        run_processes_parallel_start_as_needed(&pp);
    }

This eliminates the need for the flag and also exits the loop just after the possible startup of new processes.